Piston for hydraulic presses



UNITED STATES ATENT OFFICE.

LEWIS MILLER, OF PHILADELPHIA, PENNSYLVANIA.

PISTON FOR HYDRAU LIC PRESSES.

SPECIFICATION forming part of Letters Patent No. 402,955, dated May '7, 1889.

Application filed January 17, 1889. S rial No, 296,577. (No model.)

To all whom it may concern.-

Be it known that I, LEWIS MILLER, a citi= zen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Pistons for Hydraulic Presses, of which the following is a specification, reference being had to the ac companying drawings, in which- Figure 1 represents a transverse vertical sectional view of my improved piston; Fig. 2, an end elevation; Fig. 3, an enlarged sectional view of a portion of the piston, showing the packing-rings compressed to compensate for wear; and Fig. 4, a detail view of one of the packing-rings.

The invention relates particularly to the packing and the means employed for adjusting the same to compensate for wear; and it consists in certain novel features of construction and arrangement of parts that will be fully hereinafter described, and particularly pointed out in the claim.

In the accompanying drawings, the letter A designates the cylindrical body of the piston,

which is constructed in any suitable shape,

and is provided at its forward end with a peripheral abutting-fiange,a,and through its center with an opening for the attachment of the piston-rod. Adapted to embrace and fit snugly the periphery of the piston and abut against the flange a at its forward end are the independent packing-rings B and B, the former of which are rectangular and the latter circular or round in cross section, as shown. The rectangular rings B are constructed of any of the well-known water-packing materials of a flexible or expansible nature, and the rings B are constructed of some harder material preferably hard gum or metal. The rings are formed continuous without joints of any kind. As will be observed, the round rings are inserted between the rectangular rings, where by, when pressure is brought to bear upon the,

outermost ring, the convex surface of the round rings will be forced or pressed into the adjacent faces of the square rings, and thereby expandthe latter and force them against the interior of the cylinder in which the piston is working. To thus compress the packing rings to compensate for wear of the same, I employ set-screws O, and tap them into a ring, D, bolted to the end of the piston, the said set screws being provided with binding-nuts O,

to prevent them working loose when once set. The inner ends of the set-screws bear upon a metallic ring, E, and this ring in return bears upon the packing-rings. The interposition of this hard-metal ring prevents the set-screws injuring the packing-rings.

To adjust the rings to compensate for any wear of the same, it is only necessary to give each of the setscrews a slight turn with a wrench, the binding-nuts having of course first been loosened. The pressure will be communicated through the medium of the hardmetal ring E to all the rings alike, forcing the harder round rings into the softer rings and expanding the latter, as shown in Fig. 4.

The special advantage derived in thus constructing the packing-rings continuous and independent of each other is that any one of them may be removed when worn or injured and replaced by a new one, as is evident. By removing the ring D all the packing-rings may be readily slipped off.

It will be observed that the essential feature of this invention is the removable ring D, bolted to the end of the piston and provided with a series of setscrews adapted to bear upon a hard-metal ring or follower, E, which surrounds the piston, the set-screws being suitably tapped into the said ring D and provided with binding-nuts, as described. This special arrangement is advantageous in that it avoids screw threading the pistonbody, it being quite diflicult and expensive to accurately thread, especially a large piston, as is evident. It is also advantageous for the reason that by means of the independent set- 90 screws the ring or follower may be adjusted to compensate for any wear of the packingrings without removing the piston from its cylinder, hydraulic cylinders of this class usually having their rear ends open.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

The combination of a piston, A, provided with an annular abutment, a, independent I09 paeking ings B, surrounding the said pisscrews, substantially as and for the purpose ton, expanding-rings inserted between the set forth. 10 said packing-rings, a removable ring, D, se- In testimony whereof I affixlny signature in cured on the end of the piston, a'series of setpresence of two witnesses.

5 screws, 0, tapped in the ring D near its outer LEWIS MILLER.

edge, a hard-metal ring, E, inserted between Witnesses: the ends of the set-screws and the packing- O. D. DAVIS, rings, and binding-nuts 0 upon the said set- H. J. ENNIS. 

